Surely though the US / Israel / UK are fully aware of Iran's potential capabilities?
True Promise I and II will have been studied to the 9th degree. In addition, Israel's partial success in its response to True Promise II will have been studied in the same vein.
There must be a reason (or several reasons) why Israel thinks it could ride out a serious Iranian response. There is something hidden in all this?
I suppose you are right in some respects. Given Iran has said that it will blame the US for any attack by Israel - are the Israelis hoping for US bases to be targeted? But that seems too obvious? Iran has indicated that they do not believe that Israel could carry out strikes without US assistance. Maybe it's just case of this? Iran cannot be fooled by Trump's distancing from Netenyahu.
https://www.c-span.org/clip/news-conference/user-clip-known-knowns/4525194 Warmonger Donald Rumsfeld, in 2002, talking about, "known knowns, known unknowns and unknown unknowns". The appearance is that US/UK are aware and fearful of what the "known unknowns" and especially the "unknown unknowns" might be. The US/UK/Israel, aren't fully aware of Iran's capabilities but they are aware that Iran have capabilities that they have no intelligence about.
Iran have deliberately kept capabilities under wraps whilst simultaneously advertising that those capabilities exist, and also forced US/UK/Israel to reveal most(all?) of their defence capabilities. Iran probably has all the intel needed to destroy and bypass Israel's air defence completely should matters go hot. I think that this is the problem Empire faces, Roch.
It appears that Empire doesn't even have an answer to the "known, knowns" of Iran.